The nucleus and oocyte increase in diameter to
30.6 ± 5.8 mm and 55.5 ± 18.8 mm, respectively
(Fig. 2b). A large, round, strongly basophilic nucleolus
appears in the nucleus. The cytoplasm
remains basophilic. Follicle cells of 4.4 ± 1.3 mm in
thickness are visible around the oocytes